Portable precision tool sharpener

ABSTRACT

A portable tool sharpener mountable on a bench or the like and having an adjustable tool supporting carriage alignable with respect to a sharpening wheel to vary the degree and relief of the cutting edge of the tool to be sharpened.

United States Patent [72] lnventors Frank R. Samson 506 Arbor Drive, San Diego, Calif. 92103; Paul H. Domingues, 4516 Nido Lane, San Diego, Calif. 92117 2] Appl. No. 845,448 [22] Filed July 28,1969 [45] Patented July 6, 1971 [54] PORTABLE PRECISION TOOL SHARPENER 1 Claim, 4 Drawing Figs.

[52] U.S.Cl 51/71, 51/74 BS, 51/225, 5l/2l9 [51] 1nt.Cl B24b 7/00 [50] FieldoiSearch 5l/71,74 BS, .1, 72.2, 225, 219

[56] References Cited UNITED STATES PATENTS 587,537 8/1897 Van Norman 51/225 675,609 6/1901 Pashley 51/225 1,230,111 6/1917 Callaway 51/225 1,596,727 8/1926 Goldberg .1 51/225 1,662,078 3/1928 Severson 51/225 1,679,413 8/1928 Einstein 51/225 1,682,459 8/1928 Albertsonn 51/219 1,981,174 11/1934 Hille 51/225 2,213,756 9/1940 Zwick..... 51/225 2,368,342 H1945 Zwick 51/219 2,396,281 3/1946 Noble et a1. 51/225 2,694,882 11/1954 Edwards A 5 H722 2,785,591 3/1957 Hildebrant 51/225 3,156,074 11/1964 Baltz 51/225 3,365,843 l/l968 Robinson 51/225 Primary ExaminerWilliam R. Armstrong Atlorneys--J. C. Warfield, Jr., George .1. Rubens and John W.

McLaren ABSTRACT: A portable tool sharpener mountable on a bench or the like and having an adjustable tool supporting carriage alignable with respect to a sharpening wheel to vary the degree and relief of the cutting edge of the tool to be sharpened.

PATENTEU JUL 6 I9?! SHEET 1 OF 2 INVENTORS FRANK A. SAMSO PAUL H. DOM/NGUES (l m L ETORNEYS PATENTEI] JUL 6|97l 3590.533

SHEET 2 UP 2 INVENTORS FRANK R. SAMSON BYPAUL H. DOM/NGUES ATTORNEYS PORTABLE PRECISION TOOL SI-IARPENER STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION Various types of precision tools such as pilot reamers, spot facers, end mills, core drills, etc., collectively referred to in this patent application as tools, require frequent sharpening. This condition is particularly prevalent in tools used to machine metals in high performance aircraft capable of withstanding high stress and heat. In large machine shops, tools of this type requiring sharpening are normally sent to a special sharpening section having a Universal grinding machine and the tools are not returned to the machinist for several days. In small shops unable to afford such an expensive grinder, the tools are contracted to an outside shop for sharpening which is both costly and time consuming. This situation is aggravated where the machining operation is being performed at remote repair stations where the job may be unduly delayed in waiting for the return of sharpened tools.

SUMMARY OF THE INVENTION The portable tool sharpener of this invention comprises a bed for supporting a carriage on which is positioned the tool to be sharpened, and for supporting-a mount for the grinding wheel and a motor for driving the grinding wheel. The sharpener can e transported around the machine shop to the site of the machining operation and rested on a workbench, or preferably secured to a conventional hard vise to be operated by the same machinist when the need arises. The carriage is slidably longitudinally on the bed to feed the tool to and from thisgrinding wheel, and is slidable in a transverse direction to adjust the amount of relief required on the cutting edges of the tool. The motor mount preferably has coarse and fine adjustments for positioning the grinding wheel with respect to the tool.

STATEMENT OF THE OBJECTS OF THE INVENTION An object of this invention is to provide a portable precision sharpener-for tools such as drills, reamers, and the like that can be used by a machinist at the site of the machining operation.

Another object of the invention is to reduce the cost and the overall time required to sharpen precision tools.

A further object is portable precision tool sharpener that is simple and inexpensive in cost and more readily available to machine shops unable to purchase a costly grinder.

Still another object is to provide such a device that can use conventional grinding wheels and power sources for driving same, and which tolls are normally available in a machine shop. 4

A further object is to provide a portable tool sharpener that can sharpen a variety of difierent types of drilling tools.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS F lGlTis a top perspective view of a portable tool sharpener according to this invention with a pilot reamer tool supported thereby ready to be sharpened;

FIG. 2 is a bottom view of the portable sharpener;

FIG 3, is a side elevation view of the sharpener of FIG. 1 takenfrorn the opposite side; and

FIG 4'is an enlarged partial diagrammatic view of a reamer to besli'arpened in contact with the grinding resin wheel.

Referring to the drawings where like reference numerals refer to similar parts throughout the figures, there is shown in FIG. 1 the novel tool sharpener 10 of this invention. The sharpener comprises a rectangularly shaped bed 12 which is portable and can be supported on a machinists workbench or preferably clamped in a hard vise usually found on the workbench (not shown).

The top surface of bed 12 is formed. with a pair of recessed tracks 14 along both longitudinal edges and a pair of intermediate spaced rails IS on which slidaibly mounts a lower carriage section 16 of a split-carriage 18. An upper carriage section 20 has a vertically extending V-shaped groove 22 capable of supporting a tool 24 to be sharpened, a pilot reamer being illustrated in the drawings. The surface of upper carriage section 20 containing groove 22 is disposed at a 45 angle with the horizontal to provide a corresponding angle on the cutting edge, in a manner to be described. A horizontal upper surface of carriage 20 is provided with a vertical bore 25 to support an end mill tool, not shown, for sharpening.

Upper carriage section 20 is transversely slidably in a groove 26 milled in lower carriage section 16 by means of foot portion 27. A bolt 28 (see FIG. 2) is threaded to the bottom of foot portion 27 and extends downward through a transverse milled slot 29 in the lower carriage. By means of bolt 28 and a retainer washer, the upper carriage 20 is clamped to lower carriage section 16 in any selected transverse position of the upper carriage depending on the diameter of the grinding wheel and/or the amount of relief desired on the cutting edges, which can be determined from tables in a machinists handbook.

Longitudinal movement of carriage 1.6 in track 14 is limited by a stop 34 slidable in a longitudinal slot 35 formed in bed 12, the stop being lockable in any desired position by screw 36 (see FIG. 2). As is apparent, stop 34 limits movement of the tool into the grinding wheel to prevent an excessive cut.

Reamer 24 is supported longitudinally in inclined groove 22 by a disc 37 (see FIGS. 2 and 3) against which the shank end of the reamer rests, disc 37 being slidably mounted on one end of a rod 38 which is threaded at 39 into upper carriage section 20. Adjusting disc 37 is locked in the adjusted position along the rod by a set screw 40 depending on the length of the tool. Bed 12 is formed with an elongate slot 41, parallel to and adjacent slot 35, to provide clearance for rod 38 and supporting disc 37 which project therethrough.

A split-motor mount 42 is supported at one end of bed 12 by a pair of spaced vertical rods 44 which slidably extend through motor mount 42 and bed 112 and are secured thereto by a pair of screws 45 for locking the motor mount in a finally adjusted position. A lower motor mount half 46 and an upper mount half 48 are provided with oppositely disposed cradle surfaces 49 between which is clamped, by means of a pair of bolts 50, a motor 51, which may be provided with a source of air pressure via hose 52 normally available in a machine shop. Motor 51 drives a suitable grinding wheel 53, a resin type being illustrated. Cradle surfaces 49 are formed with a 45 slope being parallel with the rotational axis of motor 51 and with the slope of V'shaped tool supporting surface 22 so that grinding wheel 53 will move horizontally and cause a 45 cut on the tool surface to be sharpened, as will be described under Operation" with reference to FIG. 4. Motor mount 42 is secured vertically with respect to bed 12 by a pair of lock screws 56 which extend horizontally through lower mount half 46 to engage the respective rods 44 and secure the motor mount in the finally adjusted vertical position.

An adjusting screw 58 extends from the bottom through bed 12, adjacent one of the rods 44, to abut against the .bottom surface of lower mount 46, screw 58 acting as a microfeed in moving the grinding wheel into engagement with the workpiece in a manner to be described. Obviously, locking screws 56 are backed-off during the adjusting operation.

A conventional indexing finger 60 is supported in a horizontal position over the workpiece by a slotted holder 61 vertically mounted to one side of upper carriage 20 by a bolt 62 which enables indexing finger 60 to be vertically adjusted with relation to the workpiece, i.e., reamer, or pivoted upwardly away from the workpiece to permit the latter to be rotated for grinding an adjacent surface.

OPERATION The sharpening of pilot reamer 24 will be briefly described with reference to FIG. 4. First, loosen all stops and lock screws. Position the shank 24a of the pilot portion of the reamer in the'V-shaped groove 22 of upper carriage 20. For accommodating shorter tools, i.e., less than 3 inches in length, a strap, not shown, is adapted to be secured to a pair of tapped apertures 64 on lower carriage 16 to clamp the tool in position to be sharpened.

Carriage 18 is then slid directly under grinding wheel 53, and while holding the carriage, motor mount 42 is pushed down until the grinding wheel almost touches land portion 24b of reamer (see FIG. 4). Microscrew 58 is then screwed upward until it abuts against bottom of motor mount 42. While holding reamer on carriage with fingers, making sure flute 24c containing surface to be sharpened is vertical to axis of cutting wheel, slide reamer 24 until flute just touches the grinding wheel. Still holding reamer firmly in carriage, slide adjusting disc 37 up rod 38 until it engages shank end of reamer and secure set screw 40. Slide carriage 18 into the grinding wheel until flute 24c and land 24b are touching simultaneously. Slide carriage stop 34 until it engages lower carriage l6 and lock by screw 36 (FIG. 2). The grinding wheel can advance no further into the reamer than the position permitted by stop 34. Slide upper carriage to the selected transverse position and lock by means of nut 28. As previously described, the transverse position of upper and lower carriages 20 and 16, respectively, are dependent in the diameter of the grinding wheel and/or the amount of relief desired on the flutes which information can be determined from tables in the Machinists Handbook. Indexing finger 60 is raised by holding 61 until the finger is about one thirty-second of an inch below the cutting edge of flute 24c and locked in place. The indexing finger is then slid through holder 61 in toward the reamer until it butts against and is just under the cage of the major diameter of the flute, bearing in mind that the cutting edge of the flute must be vertical to the axis of the grinding wheel. Slide carriage l8 and reamer into the grinding wheel. The carriage at this point should be against the back stop and the grinding wheel touching the cutting edge of the flute and just touching the pilot. If the wheel is not touching the pilot, move stop 34 until it does. Also, if the grinding wheel is not touching the cutting edge of the flute, back off on microscrew 58, unlock screws 45, and press down on motor mount 42 until the grinding wheel just touches the reamer flute. Estimate 0.002 inches to 0.003 inches touch of the wheel against the cutting edge of the flute, making sure grinding wheel is not contacting an adjacent Start motor holding reamer firmly in carriage slot with left hand. Hold pilot of reamer with right hand with slight twist pressure against indexing finger. Run carriage and reamer until carriage hits stop. Withdraw carriage and reamer and repeat until all flutes have been sharpened.

Vertical bore 25 can be utilized for supporting spot facers and end mills to be sharpened, the operation being similar to i that previously described.

The tool sharpener of this invention provides a portable device that can be moved throughout a machine shop to the location of the machining operation or transported to a field installation where it performs an invaluable service. This portability feature ensures a substantial savings of tooling costs and materially reduces the time expended in the tool machining procedures. The sharpener is simple to operate and can be mastered by any machinist in a matter of minutes. The particular embodiment illustrated in somewhat a crude model and it is obvious that many improvements can be made for purposes of production. As previously mentioned reamer 24 and motor 51 are supported on a 45 s lope so as to provide a 45 cut on the reamer when the carriage is moved horizontally. To cut any other degree angle on the workpiece, the slope of the parts of the sharpener will have to be changed accordingly to provide the desired cut.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What we claim is:

1. A portable tool sharpener comprising:

a bed adapted to be detachably secured to a workbench,

a carriage member slidably mounted on said bed, for longitudinal and transverse movement thereon,

said carriage having means for supporting a drill-like tool to be sharpened;

means for adjusting the longitudinal position of said tool on the carriage,

a mount member slidably mounted on said bed for supporting a conventional portable motor and a grinding wheel to be driven by said motor;

means for detachably clamping said motor to said mount member,

the axis of said motor and the axis of the tool supporting means being parallel and angularly inclined with respect to the plane of the bed,

whereby the grinding wheel can be advanced with respect to the carriage to sharpen a selected surface on said tool parallel to said bed. 

1. A portable tool sharpener comprising: a bed adapted to be detachably secured to a workbench, a carriage member slidably mounted on said bed, for longitudinal and transverse movement thereon, said carriage having means for supporting a drill-like tool to be sharpened; means for adjusting the longitudinal position of said tool on the carriage, a mount member slidably mounted on said bed for supporting a conventional portable motor and a grinding wheel to be driven by said motor; means for detachably clamping said motor to said mount member, the axis of said motor and the axis of the tool supporting means being parallel and angularly inclined with respect to the plane of the bed, whereby the grinding wheel can be advanced with respect to the carriage to sharpen a selected surface on said tool parallel to said bed. 